Re: Memory locking limit and zero-copy migrations

[Fangge Jin <fjin@xxxxxxxxxx>]

On Thu, Aug 18, 2022 at 10:46 AM Fangge Jin <fjin@xxxxxxxxxx> wrote:

I can share some test results with you:

1. If no memtune->hard_limit is set when start a vm, the default memlock hard limit is 64MB

2. If memtune->hard_limit is set when start a vm, memlock hard limit will be set to the value of memtune->hard_limit

3. If memtune->hard_limit is updated at run-time, memlock hard limit won't be changed accordingly

And some additional knowledge:

1. memlock hard limit can be shown by ‘prlimit -p <pid-of-qemu> -l’

2. The default value of memlock hard limit can be changed by setting LimitMEMLOCK in /usr/lib/systemd/system/virtqemud.service

Or /usr/lib/systemd/system/libvirtd.service here. 

BR,

Fangge Jin